I'm not talking about traction roll, when you have less unsprung weight you could use softer springs and dampers without affecting the roll compared to more unsprung weight and harder springs and dampers. This will create more overall traction.
The same goes for the rollcentre, lower CG means you can get away with a lower rollcentre without having more roll compared to a high CG and a high rollcentre. Again more overall grip.

According to my calculations I can go one step softer in the springs department and drop my damper oil from 500cst to 400cst without changing overall balance or roll of the car. It will only have more grip.
I have made an Excel file which does all of these calculations, normally I use it to setup the 1:1 cars at work but last season I adapted it to my NT1 and it get's better every time I work with it.

To quote one of the pioneers of modern day motorsport 'To add speed, add lightness'
I think you should have your car as light as the regulations let you.
Of course you have to do this wisely and not just buy every single lightweight hopup and throw it on your car.
But lowering a part is always good and I think it is worth it to spend some time on this.

And yes, I immediately agree that lowering or reduce the weight of your heatsink is more important as lowering your throttle servo.
I'm also working on a lighter heatsink. First I will adept a stock RB one, but I'm also planning to make one myself on a lathe, can't be that hard.

I needed exactly 0 grams to balance my car, probably because of the lower throttle servo.

And I would love to race electro in the winter, but since I'm still in University my fundings are limited and I know myself good enough that when I would start with electro it had to be fully tricked out as well.